Colocasia plant named ‘Tropical Storm’

ABSTRACT

A new cultivar of  Colocasia  plant named ‘Tropical Storm’ that is characterized by very compact, prolific basal branching and leaves which are purple-black in color except for a prominent contrasting cream-yellow central streak.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

This invention was made with Government support under Grant No.2005-31100-06015/HAW00948H awarded by the U.S. Department ofAgriculture. The Government may have certain rights in this invention.

Genus and species: Colocasia esculenta.

Variety denomination: ‘Tropical Storm’.

BACKGROUND OF THE NEW PLANT

The present invention relates to a new and distinct variety of Colocasiacommonly known as the taro plant or elephant ears. Colocasia is grown asa food crop and for use as an ornamental plant in containers or in thelandscape. The new cultivar is known botanically as Colocasia esculentaand will be referred to hereinafter by the cultivar name ‘TropicalStorm’.

Colocasia is a tuberous rooted perennial which is native to tropicalAsia and Polynesia. Native plants of Colocasia grow to 1.5 m to 2 m inheight from starchy tubers. The leaves of Colocasia are heart-shaped andtypically are very large in size.

The new Colocasia variety named ‘Tropical Storm’ is the product of aformal breeding program carried out in a cultivated area in Kula, Hi.The purpose of the breeding program is to develop new commercialvarieties by combining attributes not found in currently commerciallyavailable varieties.

‘Tropical Storm’ is a seedling selection from the controlled pollinationof the Colocasia variety named ‘Black Magic’ (unpatented) as the femaleparent variety by brushing pollen from the Colocasia variety ‘Nancy'sRevenge’ (unpatented) as male parent. Seeds were allowed to maturewithin the developing fruits that formed after pollination. Seeds wereremoved around 45 days after pollination, and sown. From the resultingseedlings, the inventor selected ‘Tropical Storm’ in 2007.

‘Tropical Storm’ exhibits a compact plant habit with multiple basalbranches giving rise to a high leaf count. The leaves of ‘TropicalStorm’ are purple-black in color except for a prominent contrastingcream-yellow central streak.

The most commonly employed means of asexual propagation of the genusColocasia is the excision and replanting of a shoot which consists ofthe apical 1 cm to 2 cm portion of the plant corm with the attachedbasal 15 cm to 20 cm portion of the petiole. In regions of the worldwhere Colocasia is grown, this plant shoot is known as a “huli”, and themeans of propagation is known as “huli propagation”. Asexual propagationby “huli propagation” of ‘Tropical Storm’ began in 2007 at 454 MaunaPlace, Kula, Hi. by the inventor using huli propagation whereby theapical shoots are separated from the plant by cutting the shoot at thetop of the corm immediately above the newest leaf scar and planted.Evaluation in field and pot studies have shown the unique features of‘Tropical Storm’ to be stable, uniform, and reproduces true to type insuccessive generations of asexual propagation.

SUMMARY

The following traits have been repeatedly observed and represent thedistinguishing characteristics of the new Colocasia cultivar ‘TropicalStorm’. These traits in combination set ‘Tropical Storm’ apart from allother existing varieties of Colocasia known to the inventor. ‘TropicalStorm’ has not been tested under all possible conditions and phenotypicdifferences may be observed with variations in environmental, climaticand cultural conditions, however, without any variance in genotype.

-   -   1. Plants of ‘Tropical Storm’ are very compact and exhibit        prolific basal branching with high numbers of petioles and        leaves.    -   2. The leaves of ‘Tropical Storm’ are purple-black in color,        except for a prominent contrasting central streak which is        cream-yellow in color.    -   3. The leaves of ‘Tropical Storm’ are presented slightly folded        or cupped.    -   4. The leaves of ‘Tropical Storm’ are borne on glossy        burgundy-red colored petioles.    -   5. The underside of the leaves of ‘Tropical Storm’ exhibit        burgundy-red veins.    -   6. The upper and lower surfaces of the leaves of ‘Tropical        Storm’ are matte.

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying color photographs illustrate the overall appearance of‘Tropical Storm’ showing the colors as true as it is reasonably possibleto obtain in colored reproductions of this type. Colors in the drawingmay differ from the color values cited in the detailed botanicaldescription, which accurately describe the actual colors of the newvariety ‘Tropical Storm’.

FIG. 1 shows a mature plant of ‘Tropical Storm’ in the foreground.

FIG. 2 shows a close-up of the leaf of ‘Tropical Storm’.

The photographs were made from a plant which is approximately 12 monthsold from a tissue culture division and which had been grown outdoors inSanta Barbara, Calif. No growth regulators had been applied.

BOTANICAL DESCRIPTION OF THE PLANT

The following is a detailed description of the new Colocasia plant named‘Tropical Storm’. Data was collected from a plant which was 12 monthsold from a tissue culture division and grown outside in Santa Barbara,Calif. The color determinations are in accordance with The 2007 editionof The Royal Horticultural Society Color Chart, London, England, exceptwhere general color terms of ordinary dictionary significance are used.The growing requirements are similar to other Colocasia.

-   Botanical classification:    -   -   Genus.—Colocasia.        -   Species.—esculenta.        -   Variety.—‘Tropical Storm’.        -   Common name.—Taro or elephant ears.-   Parentage:    -   -   Female parent.—Colocasia ‘Black Magic’ (unpatented).        -   Male parent.—Colocasia ‘Nancy's Revenge’ (unpatented).-   Plant description:    -   -   Use.—Container or landscape plant.        -   Cultural requirements.—In common with all Colocasia,            ‘Tropical Storm’ thrives in high temperatures (above 70°            F.), in full sun or partial shade, and is most vigorous when            well-watered.        -   Root system.—Tuberous.        -   Roots.—Fleshy, up to 2 mm in diameter, with fibrous and fine            lateral roots; color 155B.        -   Root development.—At soil temperatures 20° C. to 25° C.,            root initials are evident within 3 days. Roots will reach            the edge of a 1 gallon container in 14 days.        -   Plant vigor.—Vigorous basal branching, forming dense canopy            of leaves and stems.        -   Plant growth habit.—Upright, domed, non-spreading.        -   Plant growth rate.—A one gallon container plant may be            produced in 12 to 16 weeks from a 4 cm cell transplant.        -   Plant description.—Once a huli or corm is introduced into            the soil and the plant is established, additional corms or            cormels are produced, attached to the original corm. These            cormels give rise to new lateral shoots. A one year old            plant of ‘Tropical Storm’ produces 25 to 35 lateral shoots.            Lateral shoots begin to appear above soil level about 6 to 8            weeks after planting of the initial plant.        -   Corm (formed at base of each petiole or huli).—Shape and            dimensions: Short cylindrical, 2 cm to 3 cm in diameter, 1            cm in height. Surface texture: Rough with root initials            (eyes). Color ranges between N186A and 202A.        -   Cormels (arising from established corm, forming base of new            lateral shoot).—Shape and dimensions: Short cylindrical, 1.0            cm to 2.5 cm in diameter, 0.5 cm in height. Surface texture:            Rough with root initials (eyes). Color ranges between N186A            and 202A.        -   Plant dimensions.—45 cm to 60 cm in height and 45 cm to 60            cm in width.        -   Plant hardiness.—USDA Zone 7b.        -   Propagation.—Propagation is accomplished by huli propagation            and by tissue culture.        -   Time to develop daughter plants.—Appear above soil around 2            to 3 months after planting.        -   Crop time.—1.5 to 2.5 months.-   Foliage (lateral shoots):    -   -   Petioles.—Shape: Round section. Petiole base enclosed within            short clasping sheath which is open along its uppermost            aspect. Length: 12 cm to 30 cm. Diameter: 2.5 mm (just below            attachment to lamina), 4 mm (as petiole emerges from            sheath), 6 mm (inside the sheath). Strength: Strong, stiff.            Color: 187B. Surface texture: Glabrous, glossy. Sap color:            Colorless.        -   Leaf.—Number: Each lateral shoot bears 1 to 5 leaves at a            time. Observed plant has 50 to 60 leaves of all ages.            Dimensions at maturity: 17 cm to 20 cm in length and 12 cm            to 15 cm in width. Average leaf sinus depth (Mature leaf):            5.5 cm. Attitude: Oblique. Aspect: Erect with apex down.            Leaf slightly folded or cupped. Shape: Sagittate. Margins:            Entire, slightly undulating. Apex: Acuminate, extends 4 mm.            Base: Peltate. Attachment: Petiolate with characteristic            tissue formed at junction of leaf blade with the upper            termination of the petiole. This area of the leaf tissue is            also known as the “piko” and is evident by virtue of its            upper surface color being similar to the color of the            petiole. The principal veins radiate from the piko. Piko            color: 187B. Leaf texture: Matte (both surfaces). Leaf color            (except central cream-yellow streak): Adaxial surface:            Ranges between N187A and N186A. Abaxial surface: N187B. Leaf            color (cream-yellow streak): Adaxial surface: Ranges between            4A and 4C. Abaxial surface (individual leaves): 154C and 1A.            Presence of cream-yellow streak: Not present on either            surface of first 3 (approximately), leaves of each lateral            shoot. From 3^(rd) or 4^(th) leaf, cream-yellow streak            increasingly evident on adaxial surface, diffused on abaxial            surface. Arrangement and dimensions of cream-yellow streak:            Adaxial surface: Dagger-shaped, extending from leaf base            (pair) along central vein and partially along lateral veins.            Streak does not extend to apex. Length: 10 cm to 12 cm.            Width (leaf base): 5 cm to 7 cm. Abaxial surface: Barely            apparent. Appears as green-yellow coloration along abaxial            central vein and lateral veins. Venation: Palmate. Veins:            Three principal veins radiating from the piko: one midrib            extending 13 cm to 16 cm from the piko to the tip of the            lamina, and one pair of veins extending towards each of the            basal lobe margins. Up to eight pairs of secondary veins            radiating from the region of the piko and from the midrib.            Vein color (both surfaces): 187B.-   Inflorescence flowers, reproductive organs and seed: None observed.-   Diseases and pests: In common with Colocasias in general, ‘Tropical    Storm’ is susceptible to attack by Tetranychus urticae, commonly    known as red spider mite. Otherwise, the inventor has not observed    that ‘Tropical Storm’ is more or less susceptible to pests or    diseases than other cultivars of the genus.

COMPARISON WITH PARENTAL LINES

Whereas both ‘Black Magic’ and ‘Nancy's Revenge’ reach a mature heightof 1.5 m to 2.0 m, ‘Tropical Storm’ is compact and reaches a matureheight of 0.45 m to 0.60 m. The leaves of ‘Tropical Storm’ areproportionately smaller than the leaves of either parent. In addition,the leaves of ‘Black Magic’ are entirely dark purple-black in color anddo not exhibit the prominent central cream-yellow streak whichcharacterizes ‘Tropical Storm’. The leaves of ‘Nancy's Revenge’ doexhibit a central cream-yellow streak: however, the predominant foliagecolor of ‘Nancy's Revenge’ is green, whereas the leaves of ‘TropicalStorm’ are predominantly purple-black in color.

COMPARISON WITH KNOWN VARIETY

The closest comparison variety in commerce known to the inventor is themale parent variety Colocasia ‘Nancy's Revenge’ whose leaves bear asimilarly prominent cream-yellow central streak. However, thepredominant leaf color of ‘Nancy's revenge’ is green and the plantheight of ‘Nancy's Revenge’ is 1.5 m to 2.0 m.

I claim:
 1. A new and distinct cultivar of Colocasia plant named‘Tropical Storm’ as described and illustrated herein.